This section introduces aspects that may be helpful to facilitating a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
Many semiconductor process tools rely on injection of one or more reaction and/or carrier gases into a plasma chamber. Gas mixing and flow characteristics are determined in part by a gas-dispersing showerhead that allows the gas or gases to flow into the chamber in a controlled fashion. Such controlled flow may result in more predictable, e.g. more uniform, processing, such as etch or depositions rates.